Carrier current communication system with infrared receiver

Abstract

Embodiments of a method and apparatus are described to transmit a data signal from a power supply unit, over existing direct current (DC) power transmission lines, to a residential gateway which includes an infrared (IR) receiver designed to receive optical signals. In one embodiment, the IR receiver is configured to receive a carrier current communication signal from the power supply unit over a pair of copper wires coupled to the IR receiver. The carrier current communication signals may be encoded by a transmission encoding logic circuit using pulse position modulation techniques. The received carrier current communication signals may be demodulated and decoded to reproduce an input data stream.

The invention claimed is: 
     
       1. An apparatus comprising:
 a power load unit coupled to a power supply unit through a direct current (DC) power transmission line pair; and 
 means for receiving a carrier current communication signal, sent from the power supply unit over the DC power transmission line pair, at a receiver in the power load unit, wherein the input connection of the receiver is coupled to the said DC power transmission line pair. 
 
     
     
       2. The apparatus of  claim 1 , wherein the means for receiving comprises:
 a first transformer having a first winding and a second winding, wherein the first winding is coupled to an input port of the receiver; 
 a first capacitor coupled to a first end of the second winding of the first transformer; and 
 a first resistor coupled to a second end of the second winding of the first transformer. 
 
     
     
       3. A method comprising:
 transmitting a carrier current communication signal from a power supply unit via a direct current (DC) power transmission line pair; and 
 receiving the carrier current communication signal at a receiver in a power load unit, wherein the receiver is coupled to the DC power transmission line pair. 
 
     
     
       4. The method of  claim 3 , further comprising:
 receiving an input data stream at a transmission encoding logic circuit in the power supply unit and modulating a carrier wave signal to include data from the input data stream using a pulse position modulation technique. 
 
     
     
       5. The method of  claim 4 , wherein receiving the carrier current communication signal comprises receiving the modulated carrier wave signal at the receiver. 
     
     
       6. The method of  claim 5 , further comprising: demodulating the received modulated carrier wave signal to form a binary voltage waveform. 
     
     
       7. The method of  claim 6 , further comprising: decoding the binary voltage waveform to reproduce the input data stream. 
     
     
       8. A carrier current communications system, comprising:
 a power supply unit: 
 a power load unit coupled to the power supply unit through a direct current (DC) power transmission line pair, wherein the power load unit comprises a receiver coupled to the DC power transmission line pair through coupling circuitry configured to receive carrier current communication signals. 
 
     
     
       9. The carrier current communications system of  claim 8 , wherein the power load unit comprises:
 a first transformer having a first winding and a second winding, wherein the first winding is coupled to an input port of the receiver; 
 a first capacitor coupled to a first end of the second winding of the first transformer; and 
 a first resistor coupled to a second end of the second winding of the first transformer. 
 
     
     
       10. The carrier current communications system of  claim 9 , wherein the DC power transmission line pair comprises a first DC power transmission line coupled to the first capacitor and a second DC power transmission line coupled to the first resistor. 
     
     
       11. The carrier current communications system of  claim 10 , wherein the power load unit further comprises: a decoder circuit having an input coupled to an output of the receiver. 
     
     
       12. The carrier current communications system of  claim 11 , wherein the power supply unit comprises a transmission encoding logic circuit coupled to the DC power transmission line pair. 
     
     
       13. The carrier current communications system of  claim 12 , wherein the power supply unit further comprises: a second transformer having a first winding and a second winding, wherein the first winding is coupled to an output port of the transmission encoding logic circuit; a second capacitor coupled to a first end of the second winding of the second transformer; and a second resistor coupled to a second end of the second winding of the second transformer. 
     
     
       14. The carrier current communications system of  claim 13 , wherein the second capacitor is coupled to the first DC power transmission line and the second resistor is coupled to the second DC power transmission line. 
     
     
       15. The carrier current communications system of  claim 12 , wherein the transmission encoding logic circuit is configured to modulate a carrier wave signal to include data from a received input data stream using a pulse position modulation technique. 
     
     
       16. The carrier current communications system of  claim 12 , wherein the power supply unit further comprises: a DC power supply coupled to the DC power transmission line pair. 
     
     
       17. The carrier current communications system of  claim 16 , wherein the power supply unit further comprises: a first inductor coupled between the DC power supply and the first DC power transmission line. 
     
     
       18. The carrier current communications system of  claim 11 , wherein the power load unit further comprises: a DC power load coupled to the DC power transmission line pair. 
     
     
       19. The carrier current communications system of  claim 18 , wherein the power load unit further comprises: a second inductor coupled between the DC power load and the first DC power transmission line. 
     
     
       20. The carrier current communications system of  claim 19  wherein the power load unit further comprises: a second transmission encoding logic circuit; a third transformer having a first winding and a second winding, wherein the first winding is coupled to an output port of the second transmission encoding logic circuit; a third capacitor coupled to a first end of the second winding of the third transformer; and a third resistor coupled to a second end of the second winding of the third transformer. 
     
     
       21. The carrier current communications system of  claim 20 , wherein the power supply unit further comprises: a second receiver; a second decoder coupled to an output of the second receiver; a fourth transformer having a first winding and a second winding, wherein the first winding is coupled to an input port of the second receiver; a fourth capacitor coupled to a first end of the second winding of the fourth transformer; and a fourth resistor coupled to a second end of the second winding of the fourth transformer. 
     
     
       22. An apparatus comprising:
 a power load unit coupled to a power supply unit through a direct current (DC) power transmission line pair; and 
 means for receiving a carrier current communication signal, sent from the power supply unit over the DC power transmission line pair, at an integrated circuit including connection devices for a received input signal, an output signal, a supply voltage, a ground connection and a plurality of adjusting or tuning devices and said received signal is input from the said DC power transmission line pair. 
 
     
     
       23. Apparatus according to  claim 22  wherein the integrated circuit is configured to receive a carrier communication signal via the said DC power transmission line pair. 
     
     
       24. Apparatus according to  claim 22  wherein the received signal is demodulated to form a binary voltage waveform. 
     
     
       25. Apparatus according to  claim 24  wherein the binary voltage waveform is decoded to reproduce a digital data stream which was initially received by a transmission encoding logic circuit.